Apparatus and method for making needle tubing

ABSTRACT

This invention is directed to tube making apparatus and method including (1) a tube forming and welding unit, (2) a verticaldrum drawing and/or sinking unit, (3) a derodding and cold blooming unit, (4) a horizontal-drum sinking unit, (5) a cleaner and straightener unit and (6) a swager to be used with all the earlier mentioned units.

United States Patent 1191 Valdeck Feb. 26 1 974 [54] QEEQE L JSE METHOD FOR MAKING FOREIGN PATENTS OR APPLICATIONS 1,118,728 3/1959 Germany 219/60 R [76] Inventor: James Valdeck, PO. Box E,

, Steamboat Sprmgs, Colo. 80477 Primary F Staubly [22] Filed; Apr. 21 1971 Assistant ExaminerL. A. Schutzman [21] A I N 135 871 Attorney, Agent, or Firm-Dayton R. Stemple, Jr.

[57] ABSTRACT 219/6! f jfgfigg This invention is directed to tube making apparatus 58 Field of Search 219/59 60 R, 61, 67, 160 methd "i (1) a 9 219/161. 228/44: umt, (2) a vert1cal-drum drawmg and/or smkmg umt,

(3) a derodding and cold blooming unit, (4) a horil-drum s inkin unit, (5) a cleaner and straight- [56] References Clted zoma g ener umt and (6) a swager to be used w1th all the ear- UNITED STATES PATENTS er mentioned uniw 3,169.182 2/1965 Oakley 219 60 R 3,581,041 5/1971 Balfanz, Jr. 219/60 R 18 Claims, 32 Drawlng Flgllres /09 1 ma 405 v I] (E 9* //0 //3 W g -n4 V //2- //5 .J. 47 b 6 22 T L 25 27 52 5 4 49 53 59 3 B aa /2 I? [7 [Q [8 1' I I I x 1 1 1! W 82 F n a/ a4 a9 44 14822 5455 yy EUD PAFENIED 3.794.803

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sum '17 0F 17 i xca- 32 APPARATUS AND METHOD FOR MAKING NEEDLE TUBING BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates generally to the forming of tubing from metal strip, welding the formed tube, drawing and sinking the welded tube, cleaning and straightening the drawn-sunk tube, tag-swaging tube ends as needed, inserting and removing mandrels for drawing tubing and the apparatus require for these various steps. Although the disclosure is specifically directed to medical needle tubing, it is obviously applicable to any small tubing between 0.010 and 0.325 final OD used in other arts.

2. Description of the Prior Art Although the prior art shows the broad steps and apparatus described in the preceding paragraph, each of the steps or units needed redesigning to consistently produce high quality tubing with a minimum of cost, wastage and noise. The drawing and cold blooming units are completely redesigned over the prior art as is the welding and quenching block and the die mounting and movement of the swagers.

SUMMARY OF THE INVENTION The tube-former welder unit provides a novel alignment of rolls, increased diameter of rolls proceeding downstream to overdraw the tubing and welding and quenching block.

The draw and/or sink unit provides an entirely novel design, including such features as tandem storage drums, movable and tandem die holders, and mandrel insertion and removal to permit continued reuse of mandrels. The cold blooming unit provides an entirely novel design, including such features as a pulling box and successive blooming rolls positioned at different angles relative to the tubing. The flexible bearings of the pulling rolls permit pulling of the welded tubing through the blooming rolls without splitting the tubing.

The sink unit provides a novel die holder and oiling mechanism and clamping mechanism for tubing ends.

The straightener unit provides a novel pulling box and particularly the belt-gear arrangement for pulling the tubing.

The swager units provide a novel design of a precise mechanism for controlling the hacker throw and swager die opening.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front perspective view of the tube forming and welding unit;

FIG. 2 is a top plan and horizontal section on line 2-2 of FIG. 1;

FIG. 3 is a vertical section on line 3 -3 FIG. 2;

FIG. 4 is a perspective view, partly sectioned of the welding and quenching block;

FIG. 5 is a vertical section on line 5-5 of FIG. 4 through a pincher roll; FIG. 6 is a perspective view of the vertical tandem tube-drawing unit being used to draw the welded tub- 8;

FIG. 7 is a perspective view of the vertical tandem tube-drawing unit being used to sink the welded tubing;

FIG. 8 is a partial perspective, partial section, showing the tandem drums and a die holder unit of the vertical tandem tube-drawing unit;

FIG. 9 is a top plan view of the tube gripper mechanism of the tandem drums;

FIG. 10 is a vertical diagrammatic view of the mandrel operation side of the vertical tandem tube-drawing unit;

FIG. 11 is a vertical section on line lll1 of FIG. 10;

FIG. 12 is an enlarged vertical section showing the mandrel in relation to the puller roll;

FIG. 13 is a partial perspective, partial section view showing a puller box;

FIG. 14 is a perspective view of the cold blooming mill;

FIG. 15 is a vertical section on line l5l5 of FIG.

FIG. 16 is a top plan view of a series of horizontal tube-sinking units and storage coil;

FIG. 17 is a side plan view of the unit of FIG. 16;

FIG. 18 is a vertical section on line 18-18 of FIG. 16;

FIG. 19 is a vertical section of the tube gripper mechanism of the horizontal drums;

FIG. 20 is a partial top plan view showing the starterdriving mechanism of the horizontal drums;

FIG. 21 is a horizontal section of the die holder of the sinking units;

FIG. 22 is a vertical section on line 2222 of FIG. 21;

FIG. 23 is a detail view of the tube guide leading into the die holder of FIG. 21;

FIG. 24 is a top plan view of the housing holding the rubber rolls;

FIG. 25 is a vertical section on line 25-25 of FIG. 24;

FIG. 26 is a top plan view of a tube cleaner and straightener unit;

FIG. 27 is a vertical section on line 2727 of FIG. 26;

FIG. 28 is a front plan view with sections broken away of the tube puller box of FIG. 27;

FIG. 29 is a vertical section on line 29-29 of FIG. 28;

FIG. 30 is a partial perspective, partial section view of a swager;

FIG. 31 is an end view showing the swager jaws closed; and

FIG. 32 is an end view showing the swager jaws open.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A continuous coil of 304 stainless steel strip 11 is mounted on a rotating table 12 so that the vertical strip 13 passes over beveled roll 14 and then rotates to become horizontal before passing through wiping unit 15 having a wet cleaning solvent, adjustable clamping pad station 17 and dry wiping adjustable clamping pad 18. The clamps are adjustable through screws 19. Various metals and their alloys may be used depending on the desired-end product. As an example, to produce a 0.125 inch diameter as-welded tube for processing into hypodermic needle tubing, a practical selection of material would be 304 stainless steel strip 0.010 inch thick, being 0.368 inch in width, which is approximately 80 feet in length per pound.

The horizontal strip 13 then passes to the tube forming unit by first passing over a female adjustable width roll 21 which aligns the strip horizontally through the use of the micrometer head adjustment 22. it next passes under female roll 23, transfers to female roll 24 and runs between female roll 24 and male roll 26. These three rolls are in precise vertical alignment and are adjustable in width to accommodate variances in strip mill tolerances. Furthermore the three rolls serve to steady and center the strip before any forming or breakdown occurs. it then passes to the first breakdown station, including an upper male roll 27 and lower female roll 28. The design of rolls 27 and 28 is such that the strip edges are formed upwardly in a desired arc. The strip then passes through stabilizing guide rolls 31 and to the second breakdown station, in cluding an upper male or tongue roll 32 and a lower female roll 33, the design of which is such that a broad arc is formed on the bottom center of the strip therefore turning the strip edges further upwardly. It then passes through stabilizing guide rolls 34 and to the third breakdown station, including an upper male or tongue roll 36 and a lower female roll 37, the design of which is such that a tightening of the are previously formed at the bottom and center of the strip occurs so that both strip edges are turned further upwardly. After this, it passes between an upper 38 and lower 39 stabilizing guide roll and then between a first pair of horizontal forming rolls 41, 41 which form the upturned strip edges toward each other. At this point, an internal diameter gas lance 42 enters the now being formed tube, to extend furter downstream as the seam opening herafter will not be sufficient to receive the lance.

The partially formed tube passes between an upper 43 and lower 44 stabilizing guide rolls and then between a second pair of horizontal rolls 46, 46 which form the strip edges into an almost closed tube, leaving an approximate gap or seam of l/ l6 inch. The tube then passes through upper 47 and lower 48 stabilizing guide rolls and then to the closing and seam guiding station, including a lower roll 52 and an upper roll 49 which houses a centered replaceable clock spring steel 0.010 inch thick seam blade 51which serve to further close the tube seam and align and steady the seam to top and center position. The tube then passes to the final closing station and between upper roll 53 and lower roll 54 which abut the open edges of the tubing.

The tube then passes through a bushing 55 into a gas box or welding chamber 56 where it immediately passes through a pair of pincher rolls 57, 57 detailed in FIG. which are horizontally adjustable by knob 40 and vertically adjustable by nut 60. The horizontal adjustable knobs are secured by a locking pin 99. Each pincher roll includes a bearing 58, a lower thrust washer 59 and an upper thrust washer 61. The bearing 58, the lower thrust washer 59 and the upper thrust washer 61 are manufactured from an electrical insulating material (such as nylon) to assure that the pincher rolls 57, 57 are insulated from electrical current. The pincher rolls 57 are mounted on a threaded spindle 101 which is assembled through a brass mounting block 102 and the entire assembly (FIG. 5) is secured by a retaining bolt 100 and locking nuts 103.

Immediately beyond the pincher roll is the welding point 62 which is followed by a carbon brush 63 which is spring 65 pressured against the bottom of welded tube 64. The carbon brush 63 directs the flow of electricalcurrents in. the most beneficial direction; which is away from the pincher rolls 57,57 andalong the tubing 64 to the brush 63' after which the tube exits from the welding chamber into the water quenching box 66 V which thetube traverses to exit through a fitted bushing 67 to remove water from the tube which then passes over drip box 68 to catch any water that may fall from bushing 67. A cover 69 is movably mounted over the quenching box guided by dovetail 104 and controlled by finger recess 80. Through the cover is a water line 71 which terminates in a series of openings 72 which are aligned, when positioned forward, above the tube 64 so that cool running water immediately comes in contact with the entire length of the tube within the quenching box. The cover also prevents water and steam escaping from the quenching box. Water is constantly removed from the box through drain 73.

Prior to this time, there were one or two pairs of pincher rolls similar to pincher rolls 57 downstream of the welding point 62. These additional rolls were brought into use, caused a movement in the molten weld puddle which weakens or destroys the seam weld. Elimination of downstream pincher rolls eliminates working of the molten weld puddle. Furthermore, the introduction of additional pincher rolls requires that the welding chamber 56 be designed larger and therefore require more shielding gas to be used. Additional downstream rolls also require longer travel and time before cooling water can be applied. The tube is welded at about 2,450 F. and the carbide precipitation range is 900 to 1,400 P. for 304 stainless steel and it is recommended that cooling through this range be very rapid. Therefore elimination of downstream. pincher rolls shortens the tube travel to less than 5 inches and preferably about 2 inches before cooling water is applied in quenching box 66 as opposed to approximately 6 inches prior to this time, causing the cooling rate to be very rapid through the carbide precipitation range. V

The welding and quenching unit .is formed and machined from a single cast block 50 with channels 78 circulating wateraround the welding chamber 56 for' cooling purposes and being transferred by flexible tube 123 to cover 69. Channel 78 has a clean-out plug 98. The cast block 50 is adjustable vertically by leveling screws 165 and horizontally by locking bolt 90 which allows complete alignment with the tube path of travel. When the tube first enters the welding chamber 56 the first inch of travel takes it to the end of the pincher rolls 57,57. After traversing another A inch, it reaches a welding point 62 and after another A inch it reaches the brush 63. inch beyond the brush the tube passes through a 6 wall section and then 2% inches through the quenching chamber 66 and a final inch through bushing 67.

Eddy currents are eliminated or reduced to a minimum by insulating the pincher rolls 57 and providing brush 63 immediately downstream of the welding point and grounding the entire casting at 79. Then brush 63 which is mounted in a brass sleeve is threaded directly in the welding casting 50 and is tensioned by the brush adjusting screw through carbon brush spring 65. Thusly the brush 63 directs current to the work or ground 79. 

1. A process for making metal tubing continuously from a metal strip comprising forming said strip to a tube by passing through an aligned series of mating tongue and groove, idler and driven, rolls of different shapes, passing said tube into an inert gas chamber between a pair of horizontal pincher rolls positioned within said gas chamber, said pincher rolls being electrically insulated from said chamber, welding said tube downstream of said pincher rolls, electrically grounding said tubing downstream from said welding, quenching said tubing downstream from said grounding through the precipitation range prior to any further metal working beyond said pincher rolls, cutting said tubing into desirable working lengths, opening one end of said cut tubing with a swager, inserting a mandrel into said cut tubing through said open end, swaging one end of said mandrel to said tubing, drawing said tubing through a die onto a vertical drum to reduce the inside diameter of said mandrel and wall thickness and outside diameter to desired dimensions, pulling said drawn tube through a plurality of roll pairs by driving at least one of said pairs, the plane of each pair being at a different angle to bloom said drawn tubing from said mandrel, withdrawing said mandrel from said bloomed tubing, inserting said mandrel in a subsequent length of cut tubing, swaging one end of said bloomed tubing, sinking said bloomed tubing through a die onto a horizontal drum to reduce the inside and outside diameter to second desired dimensions, and passing said sunk tubing through a rotary frame having an offset peg and a plurality of centering pegs.
 2. A process for making as-welded metal tubing continuously from a metal strip including forming said strip to a tube by passing through an aligned series of mating tongue and groove, idler and driven, rolls of different shapes, passing said formed tube into an inert gas chamber between a pair of horizontal pincher rolls positioned within said gas chamber, and welding said formed tube downstream of said pincher rolls wherein the improvement comprises quenching said welded tube downstream of said welding point prior to any further working.
 3. The process of claim 2 wherein the distance between said welding strip and beginning of quenching is less than 5 inches.
 4. The process of claim 2 wherein the distance between said welding step and beginning of quenching is about 2 inches.
 5. The process of claim 2 wherein said metal is 304 stainless steel and the quenching is through precipitation range thereof.
 6. The process of claim 2 wherein said pincher rolls are electrically insulated from said chamber and said welded tube is passed over an electrically grounded brush between said welding and quenching steps.
 7. The process of claim 2 wherein said driven rolls are of progressively increased diameter in the downstream direction to overdraw said tubing.
 8. The process of claim 7 wherein said increased diameter is about two-thousandths of an inch at each succeeding driven roll.
 9. The process of claim 2 wherein the distance between said welding step and beginning of quenching is less than 5 inches, said pincher rolls are electrically insulated from said chamber, said welded tube is passed over an electrically grounded brush between said welding and quenching steps, and said series of rolls are of progressively increased diameter in the downstream direction to overdraw said tubing.
 10. Apparatus for making metal tubing continuously from a metal strip, said strip and thereafter said tubing forming a longitudinal working axis, comprising a series of mating, idler and driven, tongue and groove, forming rolls of different shapes that in successive steps turn said strip into tubing with abutting edges, means for simultaneously driving said driven rolls, means following said forming rolls for welding said abutting edges, means for quenching said welded tubing, means for cutting said quenched tubing into desirable working lengths, a first swager with a die adapted to open a closed end of said cut tubing, means for inserting a mAndrel within said open tubing, a second swager with a die adapted to swage said mandrel to said tubing, a (pair of) storage pulling drum(s) mounted vertically (in tandem) on a first horizontal axis, a (plurality of) die mounting carrier(s) mounted (in tandem) on a second axis parallel and coextensive to said first axis (, one of said ) having a fourth die(s) adapted to pass said swaged tubing and mandrel, (any of) said drum(s) adapted to draw said swaged tubing and mandrel through said (one) fourth die and store thereon whereby the internal diameter is reduced to said mandrel and the wall thickness and outside diameter are reduced to desired dimensions, a plurality of mating blooming rolls in pairs in spaced alignment along said tubing axis, the plane of each pair being at a different angle, each blooming roll spaced from its associated mate a sufficient distance to bloom said tubing from said mandrel, at least one of said pairs being driven, a mated pair of pulling rolls in alignment along said tubing axis and downstream from said blooming rolls adapted to pull said mandrel from said bloomed tubing and reinsert same into subsequent length of cut tubing, a third swager with a die adapted to swage said drawn tube end, a (second fifth die removably mounted along said tubing axis, a horizontally mounted drum adapted to sink said tubing through said (second) fifth die and onto said drum to reduce the outside and inside diameter to further desired dimensions, a rotary frame having an offset peg positioned immediate a plurality of centering pegs, said pegs positioned along said tubing axis downstream of said horizontal drum, and means to pull said tubing downstream of said rotary frame.
 11. Apparatus for making as-welded metal tubing continuously from a metal strip, said strip and thereafter said tubing forming a longitudinal working axis, including a series of mated, idler and driven, tongue and groove forming rolls of different shapes positioned along said axis that in successive stages turn said strip into tubing with abutting edges, a welding chamber surrounding said axis downstream of said forming rolls, a pair of pincher rolls positioned along said axis in said welding chamber, a welder movably mounted to weld said formed tubing at a point in said welding chamber immediately downstream from said pincher rollers, a series of mated, idler and driven, sizing rolls positioned along said axis downstream of said welding point, and means for driving one of each mated rolls wherein the improvement comprises a quenching chamber surrounding said axis between said welding point and said sizing rolls with no welded tube working elements before quenching.
 12. The apparatus of claim 11 wherein the distance between said welding point and said quenching chamber is less than 5 inches.
 13. The apparatus of claim 11 wherein the distance between said welding point and said quenching chamber is about 2 inches.
 14. The apparatus of claim 11 wherein said quenching chamber includes a cover movable from open to closed position and provided with bottom openings adapted to be connected to a water supply, said openings being aligned directly above said axis when said cover is in said closed position.
 15. The apparatus of claim 11 wherein said pincher rolls are electrically insulated from said welding chamber, and an electrically grounded brush adapted to contact said welded tubing is positioned along said axis between said welding point and said quenching chamber.
 16. The apparatus of claim 11 wherein said driven rolls are of progressively increased diameter in the downstream direction.
 17. The apparatus of claim 16 wherein said increased diameter is about two-thousandths of an inch at each succeeding roll.
 18. The apparatus of claim 11 wherein the distance between said welding point and said quenching chamber is less than five inches, said pincher rolls are electrically insulated from said welding chamber, an electrically grounded brush adapted to contact said tubing is pOsitioned along said axis between said welding point and said quenching chamber, and said driven rolls are of progressively increased diameter in the downstream direction. 